move app to app/ subdir

app/src/components/experiments/ExperimentHeaderButtons/useOnForkButtonPressed.tsx

@@ -0,0 +1,30 @@
+import { useCallback } from "react";
+import { api } from "~/utils/api";
+import { useExperiment, useHandledAsyncCallback } from "~/utils/hooks";
+import { signIn, useSession } from "next-auth/react";
+import { useRouter } from "next/router";
+
+export const useOnForkButtonPressed = () => {
+  const router = useRouter();
+
+  const user = useSession().data;
+  const experiment = useExperiment();
+
+  const forkMutation = api.experiments.fork.useMutation();
+
+  const [onFork, isForking] = useHandledAsyncCallback(async () => {
+    if (!experiment.data?.id) return;
+    const forkedExperimentId = await forkMutation.mutateAsync({ id: experiment.data.id });
+    await router.push({ pathname: "/experiments/[id]", query: { id: forkedExperimentId } });
+  }, [forkMutation, experiment.data?.id, router]);
+
+  const onForkButtonPressed = useCallback(() => {
+    if (user === null) {
+      signIn("github").catch(console.error);
+    } else {
+      onFork();
+    }
+  }, [onFork, user]);
+
+  return { onForkButtonPressed, isForking };
+};